<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>原生事件绑定的三种方式</title>
</head>

<body>
    <button id="btn1">按钮1</button>
    <button id="btn2">按钮2</button>
    <button onclick="demo()">按钮3</button>

    <script>
        //绑定事件到按钮1
        const btn1 = document.getElementById('btn1')
        btn1.addEventListener('click', () => {
            alert('这是按钮一 它被点击了')
        })

        const btn2 = document.getElementById('btn2')
        btn2.onclick = () => {
            alert('这是按钮2 它被点击了')
        }
        function demo() {
            alert('这是按钮3 它最牛逼')
        }
    </script>
</body>

</html>